usbdump: fail early if dump file is not available

This allows for less less checking by the consumer and avoids
unnecessary work if the capture cannot be written anyway.

Signed-off-by: Peter Wu <peter@lekensteyn.nl>

3 files changed, 15 insertions, 8 deletions

diff --git a/hw/usb/dev-unifying.c b/hw/usb/dev-unifying.c
index 48479a07f4..68e2928b60 100644
--- a/hw/usb/dev-unifying.c
+++ b/hw/usb/dev-unifying.c
@@ -363,9 +363,7 @@ static void usb_ltunify_handle_control(USBDevice *dev, USBPacket *p,
     int desc_len = 0;
     const uint8_t *desc = NULL;
 
-    if (s->usb_dump_state) {
-        usb_dump_submit(s->usb_dump_state, p);
-    }
+    usb_dump_submit(s->usb_dump_state, p);
 
     /* handle basic requests such as DeviceRequest | USB_REQ_GET_DESCRIPTOR */
     ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
@@ -409,9 +407,7 @@ static void usb_ltunify_handle_control(USBDevice *dev, USBPacket *p,
     }
 
 data_ready:
-    if (s->usb_dump_state) {
-        usb_dump_complete(s->usb_dump_state, p);
-    }
+    usb_dump_complete(s->usb_dump_state, p);
 }
 
 /* handle interrupt transfers (this device does not have a bulk/iso endpoint */
diff --git a/hw/usb/dump.c b/hw/usb/dump.c
index 48da328126..eb4ce336e4 100644
--- a/hw/usb/dump.c
+++ b/hw/usb/dump.c
@@ -266,7 +266,10 @@ void usb_dump_submit(UsbDumpState *s, USBPacket *p)
     uint8_t pid = p->pid;
     uint8_t ep_type = p->ep->type;
 
-    assert(s != NULL);
+    /* fail early if not configured */
+    if (!s || s->fd < 0) {
+        return;
+    }
 
     if (ep_type == USB_ENDPOINT_XFER_CONTROL) {
         // cannot get called for OUT
@@ -294,7 +297,10 @@ void usb_dump_complete(UsbDumpState *s, USBPacket *p)
     uint8_t pid = p->pid;
     uint8_t ep_type = p->ep->type;
 
-    assert(s != NULL);
+    /* fail early if not configured */
+    if (!s || s->fd < 0) {
+        return;
+    }
 
     if (ep_type == USB_ENDPOINT_XFER_CONTROL) {
         assert(pid == USB_TOKEN_IN || pid == USB_TOKEN_SETUP);
diff --git a/hw/usb/dump.h b/hw/usb/dump.h
index 1478fdc44c..08134e82e3 100644
--- a/hw/usb/dump.h
+++ b/hw/usb/dump.h
@@ -59,12 +59,17 @@ typedef struct UsbDumpState UsbDumpState;
  * direction, but setup_buf[0]. data is empty for PID == SETUP; for PID == IN,
  * data is of length setup_len. PID == OUT is not possible because handle_ctrl
  * is never called from that point.
+ *
+ * If s is NULL or if no dump file is available, no action is performed.
  */
 void usb_dump_submit(UsbDumpState *s, USBPacket *p);
+
 /*
  * complete (ctrl): setup_is irrelevant. If PID == SETUP, then the data was just
  * inserted by the "device" in handle_ctrl. Length is actual_length. If PID ==
  * IN, then data is empty. PID == OUT is again not possible (see submit).
+ *
+ * If s is NULL or if no dump file is available, no action is performed.
  */
 void usb_dump_complete(UsbDumpState *s, USBPacket *p);